Science

Left Turns Are a Pedestrian Hazard, Study Finds

A "permitted" left turn in this driving simulator illustrates the complexity - watching the signal, watching the traffic, and watching for pedestrians all at the same time

A new study finds that when turning left, many drivers fail to notice pedestrians.

Scientists at Oregon State University used a 2009 Ford Sedan surrounded by 14-foot projection screens to put drivers through a variety of turning scenarios, as well as an eye-tracking device to find out what caught the drivers' attention.

By far the most dangerous scenarios were "permitted" left turns, intersections where drivers had to wait for a gap in traffic to make their turn.

Between 4 percent and 9 percent of the time, drivers in these scenarios were so focused on oncoming traffic they didn't even see the images of pedestrians in the crosswalk.

The findings come as no surprise to David Cochran with the California Office of Traffic Safety. He says improper turning accounts for as many pedestrian deaths as drunk driving.

"And of all the turns, a left turn is the most dangerous," Cochran said.

In 2010 -- the last year Cochran's office has data for -- 545 people died in California after being struck by cars trying to make a turn.

When it comes to traffic design, says Oregon researcher David Hurwitz, "safety and efficiency are inversely related. So decisions that promote safety mean we might have to wait longer at a traffic signal."

This is one scenario, he said, where it might be worth it to force drivers to slow down.